PROJECT SUMMARY/ABSTRACT: High-need, high-cost patients (HNHC) often experience poor coordination of care, a key driver of increased cost and utilization. Healthcare organizations and policymakers are investing in care coordination mechanisms that combine health information exchange with individualized care plans to fix the fragmented care HNHC patients receive, but evidence for these approaches is limited. In 2012, the Washington State Health Care Authority (HCA), which oversees the state Medicaid program, implemented a health information exchange (HIE) across all hospitals referred to as the Emergency Department Information Exchange. As part of HIE implementation, HCA provides financial incentives to hospitals to develop individualized care plans to improve care coordination for Emergency Department (ED) high utilizers (? 5 ED visits per year). The current project seeks to apply advanced quantitative methods in causal inference, comparative effectiveness, and qualitative methods to understand gaps in our knowledge in the use of HIE-enabled care plans to improve care coordination for HNHC patients. To accomplish this research, I will link an existing Washington State Medicaid dataset to patients who received a care plan in EDIE. Working under the mentorship of experts in health service research, I will: (1) measure the impact of HIE-supported care plans on healthcare utilization among HNHC patients (2) identify subgroups of HNHC patients with lower ED healthcare utilization after receipt of a care plan (3) describe the implementation of HIE-care plans and content of care plans in HNHC patients. These studies will inform healthcare systems on ways to improve care coordination for complex patient populations. This work will also help me establish a set of skills to become an independent investigator addressing the gaps in care coordination for HNHC populations.